Abstract

The mechanism of flatband voltage roll-off (FVRO) has been investigated with capacitors fabricated on terraced oxide with various thicknesses of filmdeposited by atomic layer deposition. It is found that the FVRO is mainly controlled by the thickness of the bottom interfacial layer and is independent of thickness. This indicates that the dipole at the interface is mainly responsible for the FVRO phenomenon rather than the charges. Electrostatic analysis suggests that the disruption of the interface dipole by oxygen vacancy generated in thinner bottom interfacial layer is a potential cause of the FVRO.